Waveguide ring switches



March 11, 1958 J. s. HOLLIS ETAL WAVEGUIDE RING SWITCHES Filed May 31, 1955 INVENTOR, JOHN s. HOLLIS, mun/c5 m LONG. W z- A TTORNE X United States Patent o WAVEGUIDE RING swrronns- Ga., assignors to the United States of America as represented'by' the Secretary of the'Army' Application May 31, 1955, Serial No; 512,342

Claims. Cl;- 333 -7) This applicati'on'is a continuatiomin part ofou'r application-'Serial Number 507,516, filed May 10,1955, entitled Low-Loss" Waveg'uide Ring Switch.

invention relates generallyto lawless-waveguide s for successively connecting' an input Waveguide wane or more output waveguides;

' It" is the main object of the-inventiont'oprovidea switch ofthis type in which the losses are minimized and which is simple in construction and rapid in operation; I

In accordance with our invention the input wave is fed into a-waveguide, in the form of a toroid, which is split axially to form concentric, complementary, inner and outer waveguide sections, which can be rotated rapidly relativeto each other. The input waveguide extends into one ofsaid sections, While the output waveguides extend into the other section. By means of cooperating"circumfer'entia'l vanes suitably positioned in the inner'and outer sections in the regions of the input and output waveguides,

ener y is'permitted'to'travel in only one directionin'the ringwaveguide and reach only one of the output waveguides, depending upon its position relative to the input waveguide.

For a better understanding of the invention, together with other and further objects thereof, reference is made to the following detailed description, taken in connection with the accompanying drawing, in which:

Fig. 1-is a-plan view of the invention with'portions broken away to show the inner details;

Fig. 2 is a fragmentary perspective view of the invention on an enlarged scale with portions broken away;

Fig. 3 is a perspective view of another embodiment of the invention; and

Fig. 4 is a plan view of a modification of the invention.

In the drawings, the numeral 10 indicates an annular hollow waveguide which is axially split in the center so as to form two'complementary sections Hand 14 having an annular space 16 therebetween so that one section can be rotated relative to the other. The space 16 shou'ldbe as close as tolerances will permit. Since it islocated centrally of the'waveg'iiide where the current density is' at a minimum, the losses are minimized.

Extending radially from inside the ring 10 into the inner section 12 of the ring is aninput rectangular waveguide 18 into which the energy to be switched is applied. A numb'er of'spaced rectangular output waveguides, in thisicase two oppositely extending waveguides 20 and 22, extend from outside ring *10'into the outer section 14. Although only two output waveguides are shown any number can be arranged around the periphery of the outer section 14.

Extending from waveguides 18, 20, and 22, respectively, are a plurality of L-shaped vanes 24, 26, and 28. Each of said vanes are identical in construction so that only vane 24 will be described in greater detail. Vane 24 comprises a radially extending arm 30 and a circumferentially extending arm 32. Arm 30 forms a continuation of wall 34 of waveguide 18 and extends substantially up to split 16 of ring 10, and is of the same height as wall 34.

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Patented Mar. 11, 1958 2 Arm 32 :is, curved: and :concentric' with the walls of the waveguide sections. length otarm "32. is only attracti'on of the: width, i. e;, .th'el'on'gi dimension of rectangular waveguide 18', .andgproyides-an aperture:-through which cnergy'can flowi-trom-waveguide" 18 and through ring Waveguide "1 0' inthe clockwise direction to output'wav'e gnid'e20. Ann iii formswi-th-the outer wall of ring 10 a: waveguide hav a r adial Width equal't'o abou-t half the radial-width,- i. ea,-h-al f the'l'ongdimension, of 'ring 10, and nenee it i at cut-ofi f6i waves having afrequency which propagate in the-ring waveguide; Thisjfeature together with a'rm 30' preVentsfloWof energy in the opposite direction. Similarly, acut ofi waveguide is formed by arm 36 ofvane- 26," so that energy cannot flow past vane 26 toward output waveguide-22.

Arm 32 of input wave vane 24 extends in a counter clockwise direction,whilethearnrs 3'6 and 38 of the output waveguides extend in a clockwisedirection. The dimen- Because r1ng-waveguide-10 is split centrally, a minimum o surface currentis interrupted, so :that there is very little radiation loss even ifno choke-joints are used. However, chokescan be added to evenfurth'er reduce such losses and to improve the electrical characteristics of the'vanes,

but relatively uncritical chokes can :be used :for this purpose. 'Such chokes are shown extending upwardly and downwardlyfrom'the splits inthe upper and lowerwalls of-the ring. One choke comprises parallel, axially-extending, annularfianges 40,- 42, and 44, the latter havinga transverse 46 portion which overhangs the upper edge of flange 42. The three flanges; forman annular cavity 48 which is U shaped in cross-section, the end of one arm of the U-shaped cavity opening-into the upper wall of annular waveguide 10 in the region of the split and-the end ofthe other arm being closed. Similarly, a choke cavity is-formed-at the lower split by downwardly extending annular elements 403 42, 44', and-46's From the above description it will be' seen that-the invention herein provides a relatively simple and efiicient means for rapidly switching high frequency energy from one channel into one or more other channels. Alternativelyit may be used for successively and alternately applying energy from several different channelsinto a single channel. Thus energy from several sources conducted to Waveguides 20 and 22,- which now serve as input channels will be alternately applied to waveguide 18, which now serves as an output channel.

An alternative method of constructing-the switch is to split the ringwaveguide midway'along a transverse plane. In-such acase, the wider dimension'of the ring would extend in the axial direction, and the input and output waveguides would, as in the above case, be connected to the narrow side of the ring so that they would extend in the axial directions. Such a modification is illustrated in Fig. 3, wherein the two sections of the waveguide are superposed as shown at 112 and 114, and the split extends transversely as shown at 116. Numeral 118 indicates the input waveguide, while the output waveguides are shown at 120 and 122. A choke joint (not illustrated) can also be added.

By suitably positioning circumferential arms 32, 36, and 38 of the vanes relative to branch waveguides 18, and 22, respectively, the radial arms 28, 30, etc. of the vanes can be entirely eliminated; Such a modification is shown in Fig. 4 wherein elements which are identical to those in Figs. 1 and 2 are labelled with thesame reference numerals with a prime mark added. Except for the vane construction, the structuresin Figs. 1 and 4 are identical. The wave deflectors here take the form of circumferential vanes or septums 132, 136 and 138 of suitable length and positioned as near the borders of the slit as possible. The septums serve to divide the wide dimension of the ring waveguide into two waveguides each of which is half the width of the ring, so that they are at cutoff to: frequencies propagated in the ring. One end of each septum terminates at or near one wall of the branch waveguide, and extends along the ring in a direction which is opposite to the desired direction of propagation of wave energy in the ring. I

Numerous other changes and modifications may be made without departing from the spirit and scope of the invention, and it is aimed in the appended claims to cover all such changes.

We claim:

l. A waveguide switching arrangement comprising a main waveguide in the form of a rectangular toroid, said waveguide being split at the center of the wide wall to form two relatively-rotatable, complementary sections each of which contains one of the opposed narrow walls of the waveguide, at least one rectangular branch waveguide connected to each of said sections at the narrow wall thereof, each branch waveguide having an L-shaped vane extending from one wall thereof into said main waveguide, one arm of said L-shaped vane being a continua tion of a narrow wall of said branch waveguide and extending across said main waveguide not further than the region of said split, the second arm of said vane extending circumferentially, the second arm of a vane of one section extending in a direction which is opposite to the direction in which the second arm of a vane in the other section extends, the second arm of each vane forming with'the opposed wall of the main wave guide a region which is at cutoff to frequencies propagated in said main waveguide.

2. A waveguide switching arrangement comprising a main waveguide in the form of a rectangular toroid having its wide side perpendicular to the axis of the toroid, said waveguide being split axially at the center of the wide wall to form two relatively-rotatable,concentric, complementary sections, at least one rectangular branch Waveguide connected to each of said sections at the narrow wall thereof, each branch waveguide having an L-shaped vane extending from one wall thereof into said main waveguide, one arm of said L-shaped vane being a continuation of a narrow wall of said branch waveguide and extending across said main waveguide not further than the region of said split, the second arm of a vane of one section extending in a direction which is opposite to the direction in which the second arm of a vane in the other section extends, the second arm of each vane forming with the opposed wall of the main Waveguide a region which is at cutoff to the frequency propagated in said main waveguide.

3. A waveguide switching arrangement comprising a main waveguide in the form of a rectangular toroid having its wide side perpendicular to the axis of said toroid, said waveguide being split at the center of the wide wall to form two relatively-rotatable, concentric complementary sections, a radially-extending rectangular branch waveguide connected to each of said sections at the radiallyopposed walls of said main waveguide, each branch waveguide having an L-shaped vane extending from one wall thereof into said main waveguide, one arm of said L- shaped vane being a continuation of a narrow wall of said branch waveguide and extending radially across said main waveguide to the region of said split, a second arm of said vane extending circumferentially, the second arm of a vane of one section extending in a direction which is opposite to the direction in which the second arm of a vane in the other section extends, the second arm of each vane forming with the opposed wall of the main waveguide a region which is half the width of said main waveguide and which is at cutofi to frequencies propagated in said main waveguide.

4. A waveguide switching arrangement comprising a main waveguide in the form of a rectangular toroid having its wide side perpendicular to the. axis thereof, said waveguide having its wide side split at the center to form two relatively-rotatable, concentric complementary sections, a rectangular input branch waveguide connected to one of said sections at a narrow Wall of said main waveguide, a plurality of equally-spaced rectangular output branch waveguides at the opposite narrow wall of said main waveguidefeach section having a small septum in the vicinity of each branch waveguide and located near said split and running parallel to said narrow walls from a pointnearer one wall of each branch waveguide, said septum dividing said main waveguide into sections which are substantially half the width of said main waveguide so that they are at cutoff toffrequencies propagated in said main waveguide, eaclrseptum extending into said main waveguide in a direction which is opposite to the desired direction of wave transmission between said branch and main waveguides.

5. A waveguide switching arrangement comprising a main waveguide in the form of a rectangular toroid, said waveguide being split at the center of the wide wall to form two relatively-rotatable, complementary sections each of which contains one of the opposed narrow walls of the waveguide, a rectangular branch waveguide connected to one of said sections at the narrow wall thereof, a plurality of equally spaced rectangular branch waveguides connected to the narrow wall of the other of said sections, each branch waveguide having an L-shaped vane extending from one wall thereof into said main waveguide, one arm of said L-shaped vane forming a continuation of a narrow wall of said branch waveguide and extending across said main waveguide not further than the region of said split, the second arm of said vane extending circumferentially, the second arm of a vane of one section extending in a direction which is opposite to the direction in which the second arm of a vane in the other section extends, the second arm of each vane forming with the opposed wall of the main waveguide a region which is at cutoff to frequencies propagated in said main waveguide.

References Cited in the tile of this patent 

